This invention relates to apparatus for aerating liquids, and in particular to portable machines for preparing aerated beverages and more particularly, to a safety device for such machines.
Apparatus for preparing aerating beverages are very widely used in the home. Because of such widespread home use, safety requirements for such apparatus are particularly stringent.
In the aerating machine to which this invention refers, a bottle containing liquid to be aerated is loaded onto the machine and the gas is introduced into the machine and passed through the liquid contained in the bottle. The bottle is subsequently removed, when the aerating has been completed.
The gas used for aerating is supplied from a gas cylinder or balloon, which can be fitted onto the machine, on a part thereof hereinafter called xe2x80x9ccylinder holderxe2x80x9d, and replaced when it has become exhausted. A valvexe2x80x94hereinafter xe2x80x9cthe cylinder valvexe2x80x9d is provided to control the flow of gas from the cylinder. Usually the cylinder is rechargeable and said valve is fitted onto its outlet, but may be part of the machine in the case of disposable cylinders. The bottle containing the liquid to be aerated, is fitted on another part of the machine, which will be called xe2x80x9cthe aerating headxe2x80x9d.
Gas conduit means are provided in the machine for permitting gas to flow from the cylinder holder to the aerating head. When the cylinder valve is opened, gas passes into the cylinder holder and from it to the aerating head and through the liquid, generating an internal pressure within the machine and inside the bottle, which pressure is limited to a given maximum level by a valve, which will be called xe2x80x9cthe exhaust valvexe2x80x9d. Said pressure is called hereinafter xe2x80x9cthe system pressurexe2x80x9d. When the liquid aeration has been completed, which may be indicated by a sound produced by the exhaust valve when it opens to prevent the pressure from rising further, and the bottle is removed from the machine. In order to remove the bottle, it is tilted, and this causes a lever, hereinafter called xe2x80x9cthe tilting leverxe2x80x9d to be tilted as well. Tilting the tilting lever causes a valve to be opened and to vent the pressure within the machine to the atmosphere.
A typical way of operating the cylinder valve consists in actuating, e.g., by means of a leverxe2x80x94hereinafter xe2x80x9cthe actuating leverxe2x80x9dxe2x80x94a plunger which is in contact or in abutting relationship with a pin of the valve and, when actuated, displaces the valve pin, against the reaction of valve spring, so that it becomes detached from its seat and allows gas to flow between pin and seat. When the actuating lever is released, the reaction of the valve spring returns the valve pin to its closing position in its seat, and the plunger returns to its non-actuated position. The flow of gas from the gas cylinder to the machine and then to the bottle ceases. Another springxe2x80x94xe2x80x9cthe actuating lever springxe2x80x9dxe2x80x94returns the actuating lever to its inactive position.
A aerating apparatus of this kind is described in European Patent No. 472.995, the entire contents of which are incorporated herein by reference. This invention is not limited to its application to the apparatus of EP 472.995, since it may be usefully applied to other liquid aerating apparatus. However, it will be described, by way of example and by way of preferred application, with reference to the said European patent.
FIG. 1 represents the portion of the apparatus of the said European patent on which the gas cylinder is mounted, only the top portion of the gas cylinder being shown. Numeral 10 designates a cylinder holder. Numeral 11 designates gas cylinder, on the neck of which the body 12 of a cylinder valve is mounted, e.g. by screwing. The gas cylinder is fitted onto the cylinder holder 10, e.g. by screwing said valve body onto said cylinder holder. The valve body 12 has a valve chamber which houses spring 14. A valve pin 15, having a gasket 16, is urged by spring 14 against a seat formed in said valve body, which is provided with a bore through which a projection of the pin passes. The cylinder holder 10 is provided with an actuating lever 13, hingedly connected thereto at 18, and which can be manually depressed and is urged to its normal, inoperative position by an actuating lever spring 70xe2x80x2. When depressed, it bears upon a plunger 19 slidable in the cylinder holder and depresses it. The lowermost end of plunger 19 contacts said valve pin 15. Therefore, when lever 13 is depressed, said plunger causes said pin to be depressed, compressing spring 14 and leaving a space between the pin and its seat, through which gas can pass from the cylinder to a chamber 17 defined by inner surfaces of the cylinder holder and by the top surface of the cylinder valve, and therefrom to conduit 20, only partially shown, from which the gas passes to the aerating head (not shown in FIG. 1) on which is mounted the bottle containing the liquid to be aerated. When lever 13 is released by the operatorxe2x80x94as it may be released several times, and finally, when the escape of gas through the exhaust valve (not shown) indicates that the maximum pressure allowable within the machine has been reachedxe2x80x94spring 14 causes valve pin 15 to rise and to close the cylinder valve, thus terminating the flow of gas from the cylinder to the bottle through conduit 20.
However, should foreign material become trapped between valve pin 15 and its seating when the pin is depressed, this foreign material will prevent the pin from seating when lever 13 is released so that gas continues to flow from the gas cylinder to chamber 17 to the liquid containing bottle and/or to be discharged through the exhaust valve. While the machine is designed so that this has no harmful consequences, the user may become aware of the constant flow of gas and take some action, which action may initiate a serious malfunction of the machine and cause inconvenience to the user.
It will be understood that the aforesaid possible drawbacks are not limited to the device of European Patent 472.995, but are common to any liquid aerating apparatus in which the flow gas from a pressure gas cylinder to the apparatus and to the bottle containing the liquid is controlled by a valve that is opened by hand-actuating a mechanical element, such as a lever or the like. In any such apparatus, the possibility of the malfunction hereinbefore described exists and this invention is applicable to it.
Accordingly, it is a purpose of this invention to eliminate the aforesaid drawbacks from liquid aerating apparatus.
More specifically, it is an object of this invention to stop the flow of gas from the gas cylinder or balloon, whenever the user wishes to stop it, regardless of possible malfunctions of the valve which controls the outlet of said cylinder.
It is another purpose of this invention to provide, in a liquid aerating apparatus, in which a hand-operated mechanism is used to open the cylinder valve, to provide additional valve means, viz. means for automatically stopping the flow of gas from the gas cylinder to the aerating head and to the liquid containing bottle, if the cylinder valve has a malfunction.
It is a further purpose of this invention to assure that, should a cylinder valve pin be prevented from closing, due to wear or damage or for any reason, the flow of gas to the carbonating system is still prevented and further operation of the pin depressing means is inhibited or at least made difficult.
Other purposes of this invention will appear as the description proceeds.
The invention provides safety means for a liquid aerating apparatus, which apparatus comprises a cylinder holder for retaining a pressure gas cylinder, and an aerating head for retaining a bottle which contains a liquid to be aerated.
When the gas cylinder is mounted on the cylinder holder, an intermediate chamber is defined in said cylinder holder or between the same and the gas cylinder, for receiving gas discharged from said cylinder. A cylinder valve is provided for normally preventing discharge from said cylinder into said chamber and permitting it only when desired. Said cylinder valve may be part of the cylinder holder or may be mounted on the cylinder, depending on the type of cylinder used. In the latter case, the valve may be, e.g., screwed onto the neck of said cylinder, so that the used gas cylinder can be removed together with its valve from the cylinder holder, and substituted with a fully charged cylinder. However, the invention is equally applicable to apparatus in which the cylinder valve is fixed to the cylinder holder and the cylinder itself is, for example, disposable. In any case, when the cylinder valve is open, gas is discharged from the cylinder into the intermediate chamber. Conduit means are provided connecting said intermediate chamber to the aerating head and permitting gas to flow therethrough and, from the aerating head, to the bottle mounted thereon. Exhaust valve means are provided for limiting the pressure in the intermediate chamber, in the gas conduit means and in the aerating head to a predetermined maximum value. Since the aerating head and the exhaust valve means are not part of this invention, they will not be described herein in any detail.
Finally, valve actuating, kinematic means are provided which have an inactive and an active position. In the inactive position, they do not act on the cylinder valve, which remains closed. In the active position, they cause the cylinder valve to be opened and gas to be discharged from the cylinder to the intermediate chamber, They preferably comprise a lever and a kinematic connection whereby, when the lever is manually depressed, the cylinder valve poppet is also depressed to open said valve against the elastic reaction of elastic means, such as a helical spring and internal gas pressure. The aforesaid combination of means is part of the prior art, and is described, in a particularly advantageous form thereof, in European Patent 472.995.
According to this invention, safety means, which comprises essentially auxiliary valve means, is provided for sealing the intermediate chamber, into which gas is discharged from the gas cylinder, from the conduit means leading to the aerating head, when: a) the cylinder valve is at least partially open and permits gas to escape or leak from the gas cylinder into the intermediate chamber, and b), concurrently, the valve actuating means are in the inactive position, in which they are incapable of displacing any parts of the cylinder valve. Therefore, the intermediate chamber is only sealed when the cylinder valve is held open or partially open by foreign material, and not when it is held open by plunger 19 through pin 15 (see FIG. 1).
Said auxiliary valve means, interposed between the gas cylinder valve and the bottle containing the liquid to be aerated, comprise an inner chamber, apertures for permitting gas to pass through said chamber so as to flow from said gas cylinder valve to said bottle and means for sealing said apertures to prevent said gas flow unless said sealing means are inactivated by kinematic means. Preferably, the sealing means comprise a plunger having a first and a second surface exposed to the pressure in the inner chamber, said first surface having a larger area than said second surface, whereby to generate a pressure force actuating said plunger to seal the apertures of said inner chamber of the auxiliary valve.
In an embodiment of the invention, said auxiliary valve means comprises a control chamber, having a first aperture in communication with the intermediate chamber and a second aperture in communication with conduit means for leading the gas from said control chamber to the aerating head, plunger means for normally concurrently sealing said apertures when the cylinder valve is closed and the valve actuating means are in the inactive position and concurrently freeing them when the valve actuating means are in the active position, said plunger means having such surface areas exposed to the gas pressure in the intermediate chamber that said pressure generates a force displacing said plunger means concurrently to seal said apertures of said control chamber when the cylinder valve is not fully closed and the valve actuating means are in the inactive position
In a particularly preferred embodiment of the invention, the cylinder valve comprises a valve housing defining a valve chamber having an inlet communicating with the gas cylinder outlet and an outlet to an intermediate chamber; a poppet which has a pin slidable in said valve chamber outlet, a piston housed in said valve chamber and solid with it or attached to said pin, a seat projection in said valve housing about said outlet to the intermediate chamber, which projection can be engaged by said poppet piston in a gas-tight manner for preventing the discharge of gas from the valve chamber into the intermediate chamber, and elastic means, in general a helical spring, for urging said poppet body so to engage said seat projections
In said embodiment, the auxiliary valve means comprise a control housing which is housed in the cylinder holder, constitutes the upper boundary of said intermediate chamber, has top, bottom and peripheral walls and defines a control chamber, said top and bottom walls having each an aperture and said peripheral wall having an outer surface spaced from the inner surfaces of the cylinder holder to define a gas passage communicating with the conduit that leads the gas to the aerating head, a seat projection being defined in the lower surface of said bottom wall about said top wall aperture. A plunger is slidable in the cylinder holder and the control housing from an uppermost to a lowermost position, and comprises, from top to bottom, a stem passing through said aperture of said control housing top wall, a piston housed in said control chamber, a shank having a cross-section substantially smaller than that of said plunger stem and also housed in said control chamber, and a head slidable to seal, with the help of sealing gasket means, or free said aperture of said control chamber bottom wall. When said plunger is in its uppermost position, the plunger piston tightly engages said seat projection of said control housing and said plunger head seals said aperture of said control housing bottom wall so that said control chamber is tightly sealed. When said plunger is brought to its lowermost position by manually depressing an actuating lever, the plunger piston ceases to engage said seat projection of said control housing and said plunger head is displaced to below said aperture of said control chamber bottom wall and engages said poppet pin so as to disengage said poppet piston from said seat projection of said valve housing against the reaction of the aforesaid elastic means, whereby gas can freely flow from the gas cylinder to the valve chamber, from this latter to the intermediate chamber, from this latter to the control chamber, and from this latter to a gas passage communicating with the conduit that leads the gas to the aerating head.
In this type of apparatus, when the lever is released by the operator and is urged back by the gas pressure in the control chamber, the spring of the cylinder valve urges the poppet piston back into engagement with its seat projection, and the poppet pin, engaging the control plunger head, returns the plunger to its original position. The actuating lever is returned to its final, inactive position, by spring means, leaving a gap between it and the plunger 19. However, if the cylinder valve malfunctions for any reason, and the poppet piston is not returned to its engagement with its seat projection, or is not fully returned to it, the cylinder valve does not fully close and gas continues to be discharged into the intermediate chamber. Pressure is created in said chamber and in the control chamber and generates an upwardly thrust on the lower face of the plunger piston and a downwardly thrust on its upper face. However, the area of the lower face that is exposed to the pressure is larger than the corresponding area of the upper face, because the plunger shank has a smaller cross-section than the plunger stem. Therefore the pressure displaces the plunger to its uppermost position, wherein it seals off the control chamber and the gas cannot pass from it to the conduit to the aerating head.
In an apparatus comprising the invention, if the cylinder valve malfunctions and the gasket means, which help to seal the aforesaid aperture of said control chamber bottom wall, is damaged, and gas leakage occurs, the auxiliary valve seals the intermediate chamber off from the conduit means to the aerating head, and the pressure is not discharged from the intermediate chamber when the bottle is removed from the machine, although it is discharged from the aerating head and the aforesaid conduit means. When a fresh bottle is fitted onto the aerating head, the operator will be able to repeat the aerating operation, but will have to overcome the force exerted on the valve poppet by the pressure in the intermediate chamber and therefore will have to make a stronger effort to operate the valve actuating lever.
The safety means, and particularly the auxiliary valve hereinbefore defined, while described in connection with an apparatus as described in European Patent 472.995, are applicable in general to any liquid aerating apparatus comprising a gas pressure cylinder and a bottle containing the liquid to be aerated. The invention, therefore, generally provides safety means comprising an auxiliary valve, which comprises an inner chamber, apertures for permitting gas to pass through said chamber so as to flow from said gas cylinder valve to said bottle and means for sealing said apertures to prevent said gas flow unless said sealing means are inactivated by kinematic means. In a preferred embodiment, the sealing means comprise a plunger having a first and a second surface exposed to the pressure in the inner chamber, said first surface having a larger area than said second surface, whereby to generate a pressure force actuating said plunger to seal the apertures of said inner chamber of the auxiliary valve. The difference between the areas of the first and of the second surface exposed to the pressure in the inner chamber, is sufficient to generate the pressure force actuating the plunger to seal the apertures of said inner chamber of the auxiliary valve whenever the gas cylinder valve is not fully closed. The auxiliary valve is preferably located above the gas cylinder valve and the first and second plunger surfaces are the lower and the upper surface respectively. In a preferred embodiment, said auxiliary valve comprises an inner chamber, apertures for permitting gas to pass through said chamber so as to flow from said gas cylinder valve to said bottle and means for sealing said apertures to prevent said gas flow unless said sealing means are prevented from sealing said apertures by kinematic means.